[Backport 2.4] Fix: org.opensearch.clustermanager.ClusterManagerTaskThrottlingIT is flaky.

[opensearch-trigger-bot]

Backport 88757b4 from #5152.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: null ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/6623/
• CommitID: f74c7db
  Please examine the workflow log, locate, and copy-paste the failure below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[Poojita-Raj]

Timeout exceeded, no test failures

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/6655/
• CommitID: f74c7db
  Please examine the workflow log, locate, and copy-paste the failure below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/6664/
• CommitID: f74c7db
  Please examine the workflow log, locate, and copy-paste the failure below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[dblock]

Superseded by #5171 which has both IT test fixes.